22 



VI. Caricis Species nova, vel minus cognitce. Auctore Francisco 

 Boott, M.D., S.L.S., &c. 



In this elaborate memoir fifty-one species of Carex are fully de- 

 scribed : they are all exotic, though many of them seem to be closely 

 allied to British species. 



VII. Remarks on the Examination of some Fossil Woods, which 

 tend to elucidate the Structure of certain Tissues in the recent Plant. 

 By Edwin John Quekett, Esq., F.L.S., &c. 



The structure of spiral vessels and the nature of the markings on 

 the woody fibre of the Coniferae, having excited numerous con- 

 troversies, Mr. Quekett here gives in detail the results of his microsco- 

 pical examination of these structures in a fossil state, which go far to 

 exhibit their real nature, and are calculated to be generally interest- 

 ing to the vegetable physiologist. The first-described shows that the 

 spiral fibre is developed within the membranous cylinder with which 

 it is always associated. 



" On examining lately a specimen of fossil wood, exhibiting the 

 structure of a palm, I discovered a portion which, instead of being 

 compact like the general mass, broke down on the slightest pressure 

 into minute fragments : on submitting these to the microscope, it 

 was found that they were composed of cylinders more or less elon- 

 gated and minute rounded granules. On the cylinders there could 

 readily be observed a perfect screw, the helix being either single or 

 compound, and undoubtedly fashioned from the interior of the recent 

 spiral vessels, which fact gives the most satisfactory proof that the 

 fibre is in the interior of the cylinder, as these siliceous casts could 

 not have been so moulded if the spiral fibre had been external. The 

 intervals between the helix show the shape of the fibre, and also show 

 that it was of a solid nature. 



" The other point that has occasionally been the subject of contro- 

 versy, is the nature of the discoid bodies on the woody tissue of co- 

 niferous plants. These have been supposed by some persons to be 

 glands ; by others to be thicker, and by others again to be thinner 

 places in the membrane forming the walls of the woody fibres. 

 Others have asserted that there is a pore in the centre of each disk, 

 which allows of a communication between adjoining fibres. Later 

 observers, however, have shown that none of the above theories is 

 altogether correct, as the disks are not proper to one woody fibre, but 

 are formed between two contiguous fibres, each contributing to the 

 formation of the disk by having a minute depression, shaped like a 

 saucer, on its exterior, which corresponds exactly to a similar depres- 



